I assume there is some sort of mode that is blocking viewable quit messages, including kills. By ops, do you mean an IRC Operator or an OP of a channel (@)?
The +c mode is usually related to blocking colours. On some networks, such as DALnet, the +m (moderated) channel mode can block quit/part messages, however, not even the ops will see them. I suggest asking in the #Help channel of the network/server you're using.
Regards,